a) Field of the Invention
The invention is directed to a coaxial drive for the object stage of a microscope.
b) Description of the Related Art
A generic arrangement of the type mentioned above is described, for example, in DE 19532008 A1 by the present Applicant.
In conventional cross-slide stages for microscopes, the two coordinate movements "X" and "Y" are actuated by the coaxial drive, as it is called. In so doing, the coaxial drive remains stationary during the X-movement. During the Y-movement, the coaxial drive moves in the Y-direction. However, this is extremely unergonomic.
It is desirable that the location of the coaxial drive remains constant so that there is a spatially fixed distance relative to the Z-fine focussing drive.
DE 3514431 A1 describes a microscope stage drive with control knobs fastened at coaxially mounted shafts, wherein the transmission of force is effected by traction means which are guided in a complicated manner and run over deflecting rollers fastened at the stage plates, wherein the slip of the traction means which cannot be completely eliminated does not enable an exactly reproducible stage position. Operation cannot be carried out with sufficient sensitivity because of the many deflections. Exact positioning, e.g., in tissue cells, in the range of a few .mu.m, is impossible.
Other solutions with stationary adjusting devices, but with considerable structural complexity, are described in DE 3027461 C2 and DE 3521047 C1. However, DE 3027461 C2 is more concerned with the uncoupling of the X-Y coordinate movement by swiveling out the coaxial drive which is connected with the X-Y movement by means of a friction wheel.
DE-GM 1978009 is directed to an object holder representing a microscope accessory which is generally fastened to a microscope stage in order to move objects over the stage plate which is usually stationary.
DE 3521047 C1 describes separate straight-line guides for X and Y. These guides are expensive, require extensive maintenance and occupy a large amount of space. The sliding of the profile axis causes shaking and noise which could disturb the concentration of the user.